SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5df8ad8aac478c30df2f630fd11f000c533eeb6694eba4ab3139eac565081ae2' 
  AND token = 'no06IMkezPBWGF/6LK0mOIiRCcCg8fenCgmvaDvD1Bo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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