SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b26a7d0c9fe20ab5b58406fb65fa215c616e992693b2e1c6a3f2747675eb27e2' 
  AND token = 'aMHESp25QBRAkSZNY/RuiJgMWPHmp1eDEDubbmWeGRs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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