SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '834ffd0e4b29c6c3b3626ba93b0044e83f4cee06791e52c805769e73234c30b2' 
  AND token = 'MnjZza/1E3zCpfcHqXEbq3NSmsWg+v2s1rYNnB+HBBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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