SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4c4935a9b014c2d688d6c71e5cf2eb15f653ac26821b6ca04d4bbc97864d837' 
  AND token = '+BBeJlqnLhiVakPuqljx9WtB24rKoqhG8YbFDX0Sd3M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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