SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03c8bafdd05a41c4c42703c4e0e6c6a8e9d65aa3dd250b20fb64bc151d673c7c' 
  AND token = 'ygoIc1imBsOHaNViVUJpdS1O31LBCoMOA9RMCQQ0n7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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