SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e67af46fc0b88d267df9e2c7083228572daddecf233c5643281db5f5ab33f55' 
  AND token = 'Q95gXzZrjLBzH/5zok0I633yZ9tLHEArYeB3yzF8arw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00072

JSON explain

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