SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82b0eec61bea9eb2163d212cdaa702597a1260fa0b16752301f2e1ca1e96107e' 
  AND token = 'hbLQKIrDZdnGj7UBuNDLyKLfT7Wime3ZOQcAOTHV8ZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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