SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e37cd52624cfa9b5372a97a84c03344682d6c845acbc4b59f5784a9d04fd6d6d' 
  AND token = 'yTrphe0RFHpWuJLfFsDoPfn2TYZEsGYJYNlU0Zy6Lzc=' 
  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"
    }
  }
}