SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccd2e42629537def0a3458ad161477fba711986718d50b192a3c4737c5dbc6dd' 
  AND token = 'tKfR/+UNOIDHDyv424hAMJDz2i8bwGyxSHKc3pf2BX0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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