SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1c7103ae55690e215f9edb4238572662a9cd26369782e90c096e942e45a0b86' 
  AND token = 'cCh7ja00x3ODbfpcsmEJTjYG8MUn2oCS1vZXkFxUYEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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