SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cbeea637fe622e485ed222b439c668eedbb5abe4236624515f0f531567a7693' 
  AND token = 'D1ok9E14svMzrF5ex7Qtoh8T4axdqfI+WZpexroJK3g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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