SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e228315f9a582403f322df3fe4a47c0d3988a2c46fe0d7509fc7bb270058963' 
  AND token = 'LQIfxNx5kVEjh805pA08YvDefLfT9+EWf4DFrJtSfH4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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