SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b97659ae933ed205782a5e9e080398520069500295ef4fc6874e4b1b78ec9339' 
  AND token = 'XMq7XmrTHjxmnGubBetV+qBPyFujoVHxez1+bQ9Yv9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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