SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f315499fbd40afb8b5b818d2f8557c1d8f3dd2ea6de9b79b0f3f142a2986d232' 
  AND token = 'yVt0qThIXyMpqq5CYNvnVaeOkL9381X4zvwx2Gy76yo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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