SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a086b266d0b318245ab4667e63e1eab9cc2f3a3c010dff3f82c8ec2f6fa49d2' 
  AND token = '/qhmwzAEydSZToJZ+EGzn3kkpqlGDWtyirvS4HbjtLI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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