SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2657b048d9498ac8286999764382d4b97896bbc4ce674ca469cbd1777271897' 
  AND token = '1zQIOaxgysq9WAfUw3m7wN5eI3LZscsde2uL8vIC9Zw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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