SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26bde7e1ddfbc8878b87054bbbbb70431316ee831860059bee373c44987fa53d' 
  AND token = 'DgVMkTrKleLo+P+25viaGWNOIxRcw8THMt7EpNhmtv4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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