SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3bf2d3e49eeb56b8b322ee7d91e56b939f90802c2aa4dcc6d37bf09eea0d1ed' 
  AND token = 'pqZmWUFHpVn+Ce/fLgdzyXPNoj+zMCJBvylyfVkNlJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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