SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f998d736555186a6684bb6255570b5f73dd675a2e23ad101ef6592a31b1a830' 
  AND token = 'pY2nFLhJqr73OUVURyguLxEAYMO29HGA/rL2K/Aazs0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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