SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e26ca5480813bf90c9acf3ab97a31dcc04cae8a4ab84ae02fb9fe35b5c09ce2' 
  AND token = 'k60NuvaKKVnPszuuZSpUqzXcwHxPQmpSnJLqj+XgR4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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