SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b4aaf49ec2cce3c8521bd6056060e29ace6ecbaae72a66db12b21fa34245d572' 
  AND token = 'Zx0tIcGlLaQs+CJ/J2Dh2tvn0IKCTW02LyiHsjNbBqY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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