SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f797c6fa8a697053655da9a24a8e3559bb748293428a83c57c593e6d28233901' 
  AND token = 'U/rxJGE5+pHPI/6hr+n9iFRRKjPsFRUu+1f3W6y3IoE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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