SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a01957625031813193996f5cf1d8d8f4a6454ec43a98fe3301898736dbf447d8' 
  AND token = 'PXJTnDitvnigEI1WrhLBqoMaM2FqeCAnNwbuC2UcF08=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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