SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32df0861d3beb984fef22d06c50c47d12f0ec4380e6df52b05957155c367dcc1' 
  AND token = 'l5inOwjExkPBniwjzZBRWzwBRR/jn/PViglHp198CTY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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