SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6ef1ccf4f34fdbe44043e77b7009b0117f700277067eff6907b4c51e89b9c60' 
  AND token = 'NurruWU1EEZREkZKCPhTou2GBA88clH7kqXqhurbUlo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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