SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee1866a5466930bee2e7152f21ce5ce02b469a7fca2b9c15be38c3e44ba3545b' 
  AND token = 'erSXSdvucygjaoagQlZ/hTWFwDvODP1gGjQA2ppAXtA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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