SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1bec6c90efec443fdc2f669ebc7064969343c595851923c7641e5159477026b' 
  AND token = 'OVWxoC563ezHswY2oSBQzCaSM6wlmfYrcxRCEQfqpeo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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