SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13e8dede51daa973212392ba4140f90ec252fa99455dd355c4edef6a4a0c1edf' 
  AND token = 'Z/IxFJYR049ybFKQYuUIvgIx13ag7yWzLsy9TBKKbH4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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