SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84af692edb84b0ddbe7b1af6b234ba2cad89576b2f945f6ea88c26bbb511d3e7' 
  AND token = 'M22SyGV4i03w7AOzYEMmQX1egUs75PP+yRXZ1A6d9Vg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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