SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '773672746a1d54e9b991714bb556ba70e4e5a724746c52866125a0a6e71a81b5' 
  AND token = 'cF8IhQLVcwf2bX2qXLoSZGYBZtb7jVsghlFFsX3vjvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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