SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e470b5974db56f090dba4c6092abde26a82ef3caefbf59212875cafa9ce2f2a' 
  AND token = '1SGF8KIkEdUb+IHHiOB57Z4WV8phAPPpaVOheUTxExA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}