SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8615de4fe58cbd4ca22bcad28d107a5200e89f5e132d4e4cc318abb9da62a45' 
  AND token = 'eAGkUaF61GjxW3HUNa+5tm9aiDdASDwBBMKnzNguQBk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}