SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61ab4cf2388ff10c5f83f44d1ca83833616cb36bafb9381fcab785f5d4bc4bee' 
  AND token = '8kWXkpJb7Dvtdhs2ZvGKw1uW2UAAbbvjIKnl4PCPO+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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