SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd23c7ee7eacf18fc9dc8e16383ac11a732c587c4d78619ea9752f02c01f4f90c' 
  AND token = 'TzwIyqJy/wRlffKMH/Nw4AzDuNliv9aiNGlmNrPc94Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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