SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa5a2faa8ad7952cb9ad4383db8fe276cf9885dbab48b4fce7baa2449bb486f8' 
  AND token = '7c7V6czsXgWeUEFg36sMLfrKsWf0nIvLMZEaP/vnr28=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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