SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80ef538fd6d3178d4f2c295d8892a371318b1046dff241bd9e35e56a3310b20d' 
  AND token = 'BwcdQHpl1ShkFu6hbWTpwwtDfXI+2lejoP6BX+ULI3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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