SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '945b9695576bafa34be638fa9128d4d69e4007ea70c989d09a1adc3b673f5df6' 
  AND token = 'rK+F4vdNlpsKZCWAcKvCkQetsHCJ1fwJnHgvfp3Xxb8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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