SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c40c1c6eefb7907dda7c6dd2a565a2d6505ec6a9b1cfee5c8f632da0aeef28e' 
  AND token = 'q8/1FimNrLHm70XyQyKEMr+woY/OnRSxucXdkT1WHiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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