SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f3b04b00d057844c0af53cdc4ff501293743c5952916f18cc98afebf8e2c94cc' 
  AND token = 'cRi6C8JgptAqBdMR9dKQw4hQ8dVovYYfq1RNY9FbW7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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