SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9151805ea68c035aa06163a729519052b42b00212cb70088022ac9eb82624d2a' 
  AND token = 'Kw3xTnrd96WUctb0JJxy+6nhIbYfcMMNkAlIjIYSU84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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