SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6c1a6fc0a77587b3526493dab7853c6b6c09e9174cebfd8441174d8e3e7a5a76' 
  AND token = 'mcnlTWQtqC56YTPHU05M6+g/SHSSOMYSTNVx0EzoGBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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