SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66948cf6d867a735cd5babee621f05d0dc6a853a9b731e69438512e46160bb4e' 
  AND token = 'vX+Z6qkY0NjqgcQdji5AcmMpnz5o5obTtoa/lLOrEAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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