SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f85290c3f3eca49b3ba6890ec18e514f4d0bb9796285f82574f67a438ba05535' 
  AND token = 'KIF3BpHYjcEOLSxYNnzNME8YEkCTdA9v0jHxNd0puIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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