SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cb2b87d3e5a2436f6862e9123811ddeba91d084ac1c3890ff1e9a6ff4b114352' 
  AND token = 'B/7ehhP/tgZF69YhneImzG/TMiXH6wG83XwhJIHq4ts=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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