SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b48aa9d4c29a3a037a9e485e3bb618e20e263b02cccae256083dc9aa1cbaf10' 
  AND token = 'DyZ8TPMV/uR0h5P7uVPcmOkbygxKwSbGISFYwHGGTCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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