SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e75e0abf888265a12296919d7304e9fa88b151924e2f433c032935423ce6d31c' 
  AND token = 'XNe/39VuBGM3Bctjv+l/i71Via5pHfDQn89A27/iYuI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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