SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd55aa138043c7856e2dc57e4c4a8bb1609eb0ed8ce3e6f7e113c0dd59f397c63' 
  AND token = 't7+soauax2Sr9p62BU8lLsmyhJwUCIfB2KQXzWO/nGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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