SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bc0f7790d73a5cd3e51c2dd2ffe61a17a33223d8e056df983fe446a6ac51754' 
  AND token = 'v6gbcmAr4cJu0t/5lImwezgnIn2uQ3CtnKNGLMXFBWc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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