SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0cc9f21bfdb4657ea274a6f0d01aa0f0db60cbc1080f9a6771de365b85ba2d22' 
  AND token = 'kK+4mrDPH/cx8kMR1CenhOkQ2tXSOADTzHYS+jIFDyE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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