SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a03eaa06ad82d9210ea752aa7a74c1715328978fe3c9833e4ae49d347808f039' 
  AND token = 'uwX9XTeRBy5AKf4DbQOLDIziZBPZRDQ8dCNWmBL3oHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}