SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d37daad0944783392a60d21eb08858e5ee4f5b517e62e2df60194e5384efb3e' 
  AND token = 'j71FYoihSh8nmvlMgqj/yCrK9HFEqUOSKYZm0xxIURE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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