SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcb79ded78199bd7f0c0d3845cd34f3498dafd3a81a981b2b6b51b1158b14df3' 
  AND token = 'GYvNcX50g/m0KvA3Tx5ZDgGhfK6Qfn72B+NYsesMZWA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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