SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e86340264bb4f47bd9f2bb3ae566e7fa3d40416104eca2372f95f435a1fdceaf' 
  AND token = 'Lvu6Hq2J4+VhscG5RdMWZhuV7qtvBkazbqF5zBRiEbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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