SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1dd613f48ffa26cc6c3bea66ea587f2375502b39334f413e8293c13d85adabb' 
  AND token = 'LsmItecLYkaF11/lqp0jlNwSz0lFAdxtyoRloMx3600=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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