SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '133fa88c91b1e4b13b0fcc5d806eae19f6e3c2a4e1e067787dbe551096267496' 
  AND token = 'quBW1hwGDuQzM/6AFr+klUfR1q/VTHkLLk/f2YHdxyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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