SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04b6968fd246c6f6119c9fbf00caebaf6429ae4544eb731b4599a984907685cf' 
  AND token = 'GEnPrvAKij1/harsnkpf6F68mvBJ4D1zfFK32g+O7jY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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