SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef9791c3d23aa01494773cb3c5db7bbabf8ffcfe1061b42b3b31d24a307649a1' 
  AND token = 'KHH/lXojYJXebmmKDH+Dqg2A4RLR70USpNdt2CXe6yM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}