SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9621ca352c2bc5c3f5e95b93c2b5f96319d5fdcaf42d05774f47993f3b395d74' 
  AND token = 'DPwtrzuwWOJWdoBDo3X4vDkmqnGLqTidyOwo7edlT5s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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