SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'faa16f5fe46e988d71a0c4e3ada796dd4d3a758cd06ff1a54248d087ea376dc4' 
  AND token = '3jXQLAAaKj2nX1xjlCdMCTsFG8lBKyN+YupA5AohyWo=' 
  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"
    }
  }
}