SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bac10919ab479a8cf2e8ff274d6630444e007098cd1a82ab7a654ab46e0add15' 
  AND token = '68fw5fJFKXzMRTOVJ0XIR9DSLF6f0vb/lLErON1P69Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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