SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'deebd4fffdab9c20abd6b62ef39f90ee000a6cee1023add5dc067ece1328895c' 
  AND token = 's34mijdMOwqeYLAFq7Ilp4lhP3WjFyplWZnz7p6RCng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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