SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f371009a09477a180fa2d58e2ab6f6fc2d0007089c27e878ebd9cae11d6faf25' 
  AND token = 'grGFUChNabXPgzC03iaXWpHKQ5lsund+HeeccNG1KRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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