SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80a1d209ccfcb4142ef9d15892aa1ed6ef54e2aece870f3a67f0b9fad2027ddb' 
  AND token = 'psKz0uEWZjEZkgF3bn9pishYuzxSawrJb6ofKCB7mt8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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