SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c48d385908f8444ded45cee852a32ed7e3c0dc9ae3dc458b7000dc94fb962b21' 
  AND token = 'rxq6wl7C3NobPps9QZL5Z+GYE/XCvNJDu/MaF7eJiYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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