SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fe9888deeef35cd0d9a16e39532ea25fc5c1e832c65c5acd29d54c8158b0fc1' 
  AND token = 'BxJ0fhIe/RoNxIZJf5erNNGVcYufdQH+n8JrczqFqqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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