SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e58a1dd091d7243f236bf0d64b811e3a6b9021a2cf6d49a20ac75c4766e4444' 
  AND token = '++5IYQwjJVv8UhZ2J51kTlGllLITJWZwjL8mwo9qA2k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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