SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39cb8a68cc8209f510c42601b9eeb3a5242323e75f3a66b34c1ef39ed79fd7b5' 
  AND token = 'x8uVL56JTgY9z20o/KheHg6EFhFYhAIYDaW2RjnuNaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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