SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ea0dabfd23678909fb822cd2671c3fb7a1cfba95d06fce3e75e7f97ee7499de' 
  AND token = 'gVDaxQo6t1VPVozeVsRvltfaEXgqBnFkKeP1BzfNELE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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