SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efa926aa6565f9756cce8ce4e1085c68e54ce9e6708bf587fbeb937a0366d555' 
  AND token = 'PEsLKQB7RadUxR7wwZBDciG58O3e8sAQ61qt6POYhSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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