SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce6e6bff19a1aeb01e6d9f3f34dadb5aeca1eabb058e1dae530ab87698081f14' 
  AND token = 'fnaWD9fsmWaZEG70xgYGSKLfEXZr46BFoatTtOHW0YI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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