SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '18feefb5e27d136e2efda69da75a4a7419dafd81912c8b8aa840cb031a315a62' 
  AND token = 'VUrohtdccBc6DpirB0FZ7C+Rck1M/9mUJZPJTexqejM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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