SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b3a8e61214550e2d4c6790dc45bd0171caf1ee3e283df942ebb97fd195f453e' 
  AND token = 'jL1x9MyZ6ToIoAm/Tba92v1Z9oU8isYLQXE6EFfeLac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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