SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ce55462c2038e92461e0b03954919ff9b23cd5180259ae7a64f70b3e7bc0683' 
  AND token = 'KBTRsXRD6JpDRLvQV2QkvvmRem4pH8+9VL9879Uj6ME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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