SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '438700f5db367bbdc4af44f013ca0c1a65cb3c7633f3b7d839c1927417b5f291' 
  AND token = 'ZF1YszqIkEFLCLJc2uuP3lOPoi2UQUorPACiKgojgcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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