SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92607c1c90832361b1eceae7fe061a827b3868d433eb14eb72fe2ba9860bec22' 
  AND token = 'pUJV6VjDNHMXd4N5mOPCprAitiuSkBaKMSjqM0m2ah0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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