SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95972df303efa5196fbb6b132cdadb51274052e82899ce395e22aa9950bb5903' 
  AND token = 'H7uV6meZFUI277TLSfBkCt0qm8cXM+0zbhrbcNM2QVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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