SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4394db3cfd8c70fabdd816047002407deb8223bd0aeeb8dcec4c7a4d7402ea9' 
  AND token = 'EwQ9phiPcIwz9etBkc+IX9noPaHD1pBqcYwkyP9/Oss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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