SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afded889b8c4e270e9c4cffad5757c628660cd9b89dc0c62f73afd4c02644cea' 
  AND token = 'wWRG5PZ638eVZdudLUCn0rF19Cpn2b9lvPB+dxY/oek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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