SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'babf86eb6097a232461e01ef7ea8d338bea041da55860f25bbbb590bdf5443b2' 
  AND token = 'GBB+60mcEqR2UOi8RrBShzLzZHzPBSfQ8hopGqjCHNA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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