SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a6d4b61d7a7dacaf4946eafed2aac53b7f70f65cb4a51464b6a2c6afd42458f' 
  AND token = 'f3K/UzRVNdtdRsXrhIGrS8D2rrPf0x1HgDM9FG6RoIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}