SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3627f5d0350c8504ffa66934262bf9e60a9a79374deb9a140fb0a6a96fbb26e9' 
  AND token = 'fE8czqjdOydSNwmQGzmN7BD4gaSklHOP8Oz7VCVG+VE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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