SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7d98172ffe29ad034ba33650ee05fe3a31c71621f1c6fdcd7f1ff91b5fabdc2' 
  AND token = 'D6rEZzmGJBTGzoDdHnwzdaem0C+4a0ABcZjLyDiSrJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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