SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0427ab144729609d328d0e5d4ae14fba39e9420137e876a496d7fd7bc9db38e4' 
  AND token = 'MpIBdkji5qF52/1PBts5Bb5OQrZhWPUmvwqkqoQYVJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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